Traveling cleaner for textile rooms



March 7, 1961 G. w. ALLRED TRAVELING CLEANER FOR TEXTILE ROOMS 5 SheetsSheet 1 Filed March 27, 1957 INVENTOR Geor e w Aumi m JW M rch 7, 1 1 G- w. ALLRED 2,973,543

TRAVELING CLEANER FOR TEXTILE ROOMS Filed March 27, 1957 I 5 Sheets-Sheet 2 INVENTOR George W. ALLIGCL BYJOMJJWVXQ 1mm ATTORNEYS March 7, 1961 e. w. ALLRED TRAVELING CLEANER FOR TEXTILE ROOMS 5 Sheets-Sheet 3 Filed March 27, 1957 G. mvmon George W. Aurd.

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ATTORNEY S' U March 7, 1961 G. w. ALLRED TRAVELING CLEANER FOR TEXTILE ROOMS Filed March 27, 1957 5 She ets-Sheet 4 INVENTOR George Aurecl.

12 JW Emmi ATTORNEYS 1w 2,973,543 Patented Mar. 7, 1961 sociated organization which changes the plane of indexing of the blower unit for each succeeding cycle of 2,973 543 operation over the angular path covered by the blower;

TRAVELING CLEANER FOR TEXTEE ROOMS George W. Allred, Mayodan, N.C., assignor to The Bahnson Company, Winston-Salem, N.C., a corporation of North Carolina Filed Mar. 27, 1957, Ser. No. 648,968

9 Claims. c1. 15-312 The present invention relates to cleaning apparatus for textile room application and more particularly to a cleaning device mounted upon a trackway located above a plurality of textile machines and adapted to travel along said trackway over the machines in order to blow elf-from the machines and from the walls and ceiling any lint or other foreign matter which may become deposited thereon. This application relates to an improvement upon the traveling cleaner disclosed in my application Serial No. 266,520, filed January 15, 1952, now Patent No. 2,823,409 granted February 18, 1958.

One object of the present invention is to provide a traveling cleaner of the type described wherein the blower unit is indexed to rotate in a generally vertical plane about a horizontal support axis. The indexingof the unit is made angulariy oscillatory for any desired angular path so as to cause the air blast for example to sweep back and forth across the ceiling or back and forth across the machines.

Still another object of the invention is to provide a blower unit for a traveling cleaner arranged in such manner that the blowing direction of the impeller is shifted in a step-by-step manner through a given angul'ar travel from an initial starting position and is then caused to reverse itself and move back to its initial position quickly and without stopping so as to start a new cycle of operation. The advantage of this arrangement is that as the blower moves along the trackway, the area first cleaned 011' when the blower made its initial angular sweep will be cleaned again without waiting for a stepby-step reversal of the cleaning-01f process. In other words, the time interval between successive clean-offs of each unit area covered by the sweep of the impeller will be substantially uniform.

A further object of the invention is to provide a blower unit for a traveling cleaner arranged so that the impeller is indexed to blow in different directions throughout a selected angle in one plane during one cycle of operation and wherein for the next cycle of operation the impeller is shifted to blow in a different plane thereby making it possible for the air blast delivered by the impeller to reach and blow off surfaces which would otherwise be most difficult to reach.

In the accompanying drawings which illustrate preferred embodiments of the inventive principles as disclosed herein;

Fig. l is a plan view of the trackway and blower unit located in the room to be cleaned;

Fig. 2 is a view in side elevation of the blowerunit, a portion of thetrackway and a plurality of the machines to be cleaned, the latter being shown in broken lines since they are obviously not part of the invention;

Fig. 3 is a view in side elevation of the blower unit drawn to a larger scale and a portion of the trackway from which it is suspended;

Fig. 4 is a top plan view of the blower unit;

Fig. 5 is a fragmentary view in perspective of that portion of the blower unit supporting structure and as- Fig. 6 is a detail showing the cam mechanism by which the plane of indexing of the blower unit is changed.

Figs. 7 and 8 are side and end views respectively of one ofthe dependent supports for the blower unit and which also carries the mechanism for indexing the blower unit;

Fig. 9 is a schematic electrical wiringdiagram for controlling the reversible motor which serves as the motive power for operating the indexing mechanism; and

Fig. 10 is a fragmentary view showing a modified detail.

With reference now to the drawings, numerals 1 and 2 designate two of a plurality of textile machines such as a knitting machine, drawing frame or spinning frame or the like located in aroom. Above the-machines is a horizontal monorail trackway'3 of the inverted T type which is suspended from the ceiling 4 by a plurality of spaced hanger rods 5. The trackway 3 forms aclosed loop as shown clearly in Fig. 1 and it will be understood that its configuration would be such as to 'pass over each machine in the room to be cleaned.

The traveling cleaner or blow unit C, as illustrated, is preferably of the conventional self-propelled type and is suspended from thetrackway 3 by means of. a wheeled carriage comprising a pair of vertically depending, longitudinally spaced supports 6, 7 between which is mounted a generally rectangular frame 8 made out of tubular material; In order to better enable the traveling cleaner to negotiate curves in the trackway, the rear support is divided into upper and lower' sections (in, 6b connected to-' gether by a pivot bearing 9. The upper section 6a is carried by a pair of wheels-1t} which roll on the horizontal flange of the trackway 3 and the front support 7 is of similar construction and is also carried by simithe same and are likewise supported by the spaced hanger rods 5. It is to be understood, however, that it is not essential to the present invention that the blower unit C be self propelled. All that is necessary is that some means he provided for moving the same along the trackway. Thus as an alternative, the blower unitmay be constructed without any propulsion means whatsoever and attached as a trailer unit to a difierent'type of selfpropelled traveling cleaner unit that may already be in operation in the room.

The rectangular frame 8 is pivotally mounted by means of trunnions 18, 19 at opposite sides 8a, 8b'thereof in bearings 20 on the front and rear supports 6, 7 for rotation' about a horizontal axis extending longitudinally of the trackway.

A motor 2.. having an impeller 22 secured upon its drive shaft 23 is fastened'within an elongated secondary frame 24 which extends transversely between the other two sides 80, 8d of frame 8, the ends of the secondary frame 24 being provided with trunnions 25 which are received in complementary bearing sleeves 26 so that the motor and its secondary frame are thereby pivotally mounted for angular adjustment within the'main frame 8 about a horizontal axis which is normal to the longitudinal axis of rotation of the main frame. quently, with the components in the positions illustrated in Figs. 3 and 4 wherein the axis of motor shaft 23 is located in a vertical plane, rotation of the main frame 8 about its horizontal axis will cause the blowing direc- Consetion of the impeller 22 to shift through a corresponding angle in the vertical plane.

A double pole, single throw switch 27 having a pivotally mounted contact actuating arm 28 thereon is supported upon a horizontal extension arm 29 of the rear support 6. A motor 30 is secured in a horizontal attitude to the underside of arm 29and attached to its drive shaft is a worm 31 which meshes with a worm wheel 32 secured to a vertical shaft'33. The upper end of shaft 33 is mounted in a bearing 34 secured to the under side of arm .29. and the lower end of shaft 33 is mounted in a bearing 35 secured to the upper side of another horizontal extension arm 36 at the lower end of support 6.

Secured upon the shaft 33 intermediate the ends thereof is a worm 37 which meshes with a worm wheel 38 secured upon a horizontal shaft 39 which-constitutes an axial extension of the trunnion 19 'on the rectangular frame 8. 7

A circular cam plate 41 having a plurality of circumferentially spaced notches 42 around its periphery is secured upon shaft39 by set screw 40. A pair, of resetting or blower angles limiting arms43, 44, can be mounted on the shaft 39 in spaced axial relation to the cam plate 41. The arms 43, 44 can be adjusted around the. shaft 39 to any desired angular distance therebetween by means of the set screws 45, 46 which thread through the hub portions of the arms and engage the surface of shaft 39. a

A double pole, single throw holding switch 47, similar to switch 27 and also having a pivotally mounted contact actuating arm 48 is secured to andlaterally offset from support 6 by, a bracket 49 such that arm 48 is located in line withcam plate 41 and a roller 48a at the outer, free end of arm 48 rides uponthe periphery of the cam into and out of the notches 42 causing the arm 48 to periodically rise and fall and hence periodically actuate switch 47, the contacts of this switch beingopen when the switch arm 48 drops into one of the notches 42, and being closed during the time that arm 48 rides the :cam surface be-- 40 tween adjacent notches.

. In the cleaner construction shown. in my aforesaid Patent No. 2,823,409, the blower motor and impeller are.

indexed back and forth inangular increments throughout a given total angular travel which may, for example, be 180.

direction are not uniform, it beingobvious, for example, that at the end portions of the angular sweep, the impeller will blow twice in the same direction with a very short time interval therebetween and then there will be a very long time interval before the impeller again reaches that same blowing direction. The present invention, however,

makes it possible to establish uniform time intervals between successive blow-offs of the same direction.

. In operation, as the blower unit travels around the closed trackway, the contact actuating arm 28 will actu ate and momentarily close the contacts of switch 27, which is of the double pole, single throw type, each time such arm is depressed by engagement with a stationary deflector 50 secured to the under side of the trackway 3. The contacts of switch 27 are normally open and are closed upon depression of arm 28. As indicated in the circuit diagram of Fig. 9, this closes the energizing circuit to motor 30 from the conductor rails 16, 17 throughleads- 51, 52, one side of a double pole, double throw switch 53 and leads 54, 55 to and through switch 27 to motor 30. Rotation of motor 30 and worm 31 will rotate worm wheel 32 and shaft 33. Rotation of shaft 33 and worm 37 will cause rotation of worm wheel 38 and shaft 39' and hence also trunnion 19 and frame 8 about its horizontal supporting axis. As shaft 39 rotates cam plate 41 also rotates and the roller 48a is caused to be lifted out of onerecess 42 onto the periphery of the cam thus raising arm 48 and closing the contacts of the normally open holding switch 47 which is also of the double poie, single throw.

The disadvantage of this arrangement is that the t me interval between successive blow-offs of the same type. As is also evident from the wiring diagram of Fig. 9, closure of the contacts of switch 47 functions to hold the motor 30 in an energized running condition after the contact arm 28 has passed by the deflector 50 and rises again thus opening the circuit at the switch 27.

As motor 39 continues to run, the shaft 39, trunnion 19, frame 8 and cam plate 41 continue to rotate until the roller 48a drops into the next succeeding notch 42 in the cam plate 41 thus lowering arm 48 and opening switch 47 and causing the circuit to motor 30 to be broken and hence stop, thus stopping shaft 39, trunnion 19 and frame 8. The next time around the trackway, the arm 28 will again be depressed thus reenergizing motor 30 and causing shaft 39, trunnion 19 and frame 8 to again rotate and turn i.e. index shaft 39 and frame 8 through an angle corresponding to the distance between adjacent notches 42 in cam plate 41. In the illustrated embodiment, there are eight of the notches 42 uniformly spaced around the periphery of the cam plate and hence the shaft 39, frame 8 and motor 21 with its impeller 22 will be indexed through steps of '45". If a smallerindexing angle is desired, the'number of notches 42 in the cam plate 41 can be increased, or vice versa. With the arrangement so far described, the indexing will proceed in a step-by-step manner, e.g. clockwise as viewed in Fig. 8 around the pivotal axis of frame 8 and shaft extension 39, thus causing the blower motor 21- and impeller 22 to index in a vertical plane thus cleaning the lint from the walls, ceiling, machinery and any other surfaces which lie in the path of the air 'olast delivered from the impeller 22.

In accordance with a principal object of this invention,

I the traveling cleaner is so constructed that the blowing direction of the impeller is shifted in a step-by-step manner through a given angular travel from a starting position and is then caused to reset, i.e. reverse itself and move back to its starting position quickly in a single step,.i.e. without stopping, so as to start a new cycle of operation. As already pointed out, the advantage of such arrangement is that as the cleaner moves along the track way, the area first blown off when the cleaner or blower made its initial angular sweep will be blown off again without waiting for a step-by-step reversal of the blowin off precess. The means for accomplishing this desirable objective is the double pole, double throw reversing switch 53 in association with the arms 43 and 44 mounted upon shaft 39 and which move in a step-by-step manner with the same. With reference to Fig. 8, and with the indexing proceeding in a clockwise direction, it will be seen that the horizontal pin extension pin 43/1 on arm 43 lies in the path of switch button 53a on the switch 53. When the pin 43a strikes button 531:, it causes the switch to be actuated from the previously described position wherein current. from the supply leads 51, 52 is led throughand out ofthe switch via conductors 54, 55, to the other position wherein the current passes out ofthe switch via the conductors 56, 57 and directly to the motor 30. However, the connections to the motor 3t? are now effectively reversed so that the motor 3% now begins to run in the opposite direction thus reversing the direction of all driven parts including shaft 39, earn plate 41 and the frame 8 which now turn counter-clockwise. The motor 30 will continue to run until the horizontal pin extension 44a on arm 44 strikes the other button 531; on the reversing switch 53, thus throwing this switch to its first described position wherein the current to the motor 30 is not direct from the supply conductors 51, 52 but rather indirectlyfrom such conductors through the switch 27 and holding switch 47 and with the motor In accordance with a further feature of the invention,

means are provided whereby the air blast produced 'by the motor 21 and impeller 22 is delivered in different planes on successive cycles of operation throughout the desired sweep angle. In the presently illustrated embodiment, the arrangement provides in successive operating cycles an angular sweep in a vertical plane transverse to the pivotal axis of the frame 8, next an angular sweep in a plane inclined forwardly from said vertical plane, as related to the direction of travel of the cleaner unit along the trackway, next an angular sweep in said vertical plane and next an angular sweep in a plane inclined rear- Wardly of said vertical plane as related to said direction of travel. The sequence then repeats itself. Such an arrangement has the advantage that the air blast reaches out at a plurality of different directions during successive cycles of operation and hence enables the blast to better reach and clean off all of the surfaces in the room on which lint and dirt accumulate and which are often difficult to reach with other types of traveling cleaners.

Reference is now made in particular to Figs. 3-6 of the drawings which best show how the plane of the sweep angle is changed with each new cycle of operation. It has already been explained that the motor 21 is secured withina frame 24 which is mounted for pivotal motion about an axis transverse to the pivotal axis of the frame 8. Depending rigidly from the. housing of motor 21 at each side thereof are a pair of parallel spaced arms 58, 59. The outer ends of the legs 66a, 6421') of a stirrup 6d are articulated to the lower ends of the arms 58, 59 respectively, and the opposite end'6iic of the stirrup is articulated to the outer end of one arm 61a of an L-shaped lever 61, the outer end of the other arm 61b of lever 61 being pivotally connected at 610 to the lower end of a vertically extending flanged plate 62 secured at the inner face of the side 8a of frame 8. Secured to the inner face of plate 62 is a vertically arranged guide sleeve '72 in which is slidably mounted a pin 63, the lower end of which is bifurcated at 63a and connected pivotally to the lever 61 at substantially the junction of the two arms thereof, The upper end of pin 63 terminates in a transversely extending head portion 63b which is secured to the inner face of a vertically extending tapered plate 64, and the plate 64 and hence the pin 63 are always urged upwardly by a vertical helical spring 65 in compression guided upon and surrounding rod 66 that extends vertically upward from the upper end of the plate 62, the upper end of spring 65' hearing against the underface of a horizontal flange 64a on plate 64 and the lower end being stopped against a similar horizontal extension 62a on plate 62. The upper portion of the plate 6?, is provided with a horizontal bearing sleeve "7 containing a rotatable shaft 623. To one end of shaft 68 is secured a rectangular cam 69 which always bears with one of its four faces dim-69d, see Fig. 6, against the head portion 6312 since the latter is always urged in the upward direction. To the other end of shaft 68 is secured a star wheel id which is adapted to strike against a stop member 71 secured to a housing 73 enclosing the rear support 6 and to be rotated a quarter-turn at each cycle of operation of the frame 3.

As indicated in Fig. 3 the stop member 371 is secured to the housing 73 by means of a pin 71a which is mounted for rotation about a vertical axis, and a spring 'iib serves to bias the pin 71a and stop 71 to a stopped position normal to the face of housing 73 so as to be in the path of movement of the star wheel 7d. Consequently, each time the frame 8 rotates in the direction of the arrows in Fig. back to its starting position, one arm of the star wheel 76 strikes the stop "71 and causes the wheel 70 and cam 69 to be rotated a quarter turn. During reversed rotation of frame 8 the arm of the start wheel is able to pass by the stop without actuating the cam since the arm is able to move the stop about its vertical mounting axis against the restoring action of the loading spring 71b.

As indicated clearly in Fig. 6,, the axis of pin 68 lies equidistant from opposite cam faces 69a and 69c but lies closer to cam face 69d than it does to cam face 6%. In the illustrated positions of the components, particularly the positions indicated by the solid lines for motor 21, impeller 22 arms 58, 59, stirrup 60 and lever 61, it will be seen that the cam face 6% bears against the head 63b of pin 63 and that the direction of the air delivered by the impeller .62 will be in a vertical plane as the frame 8 executes its angular sweep about its horizontal, fore and aft pivotal axis. When the frame 8 has executedjits angular sweep and returns to its starting position for a new cycle of operation, the start wheel 7t) will have struck against its stop 71 and rotated one-quarter turn in a clockwise direction as viewed in Fig. 6, which brings cam face 69b into engagement with the pin head 6311. Since the distance from the axis of shaft 68 to cam face 6% is greater than that to cam face 69a, the pin .63 will be forced downward thus rocking lever 61 clockwise as seen in Fig. 3 and shifting stirrup 6b and motor arms 58, 59 backward. This causes motor 21 and impeller 22 .to tilt forward as related to the travel direction to a position at an angle to the vertical. These positions of the components are shown in broken lines.

At the next cycle, the cam 69 is turned in the same direction through another quarter'turn thus bringing cam face 6% against the head 63b of pin 63. Since cam faces 69c and 69a lie at equal distances from the axis of shaft 68, the component parts are restored to the position indicatedin solid line in Fig. 3 and the direction of the air delivered by the impeller 22 is once more in the vertcal plane. At the next cycle, the cam 69 is once again rotated through a quarter turn thus bringing cam face 69d against the pin head 63b. Since .the distance from the axis of shaft 68 to the cam face 56% is less than that to the cam face 69c, the, pin 63 will move upward due to the upward loading of the pin head 63b, thus moving the lever 61 counter-clockwise and shifting stirrup 6t) and motor arms 53f59 forward. This causes motor 21 and impeller 22 to tilt backward as related to the travel direction to a new position at an angle to the vertical plane. At the end of this angular sweep, the cam face 69a is once again brought into engagement with the pin head 63b and the sequence of operations is then repeated.

To make it possible to actuate the cam 6 9,,and hence effect tilting of the motor 21 and impeller 22 for various angular positions of the arms 43, 44, the pivotally mounted stop member 71 can likewise be shifted to a corresponding position to suit the sweep angle of the impeller 22. Thus, for example, in Fig. 10 an annular plate 75 is secured to housing 73 concentric with bearing 20 and is provided with a circular array of spaced threaded holes 76. The stop 71 together with its supporting member 77 can then be secured at any desired position around the circumference of the plate 75 by means of a screw '78 which holds the stop supporting member 77 to the plate at any one of the threaded holes '76 receiving the screw 78.

It is to be understood that various changes in the construction and arrangement ofcomponents can be adopted without departing from the spirit and scope of the inventive concept as defined in the appended claims. Also, it is self-evident that by removing the arms 43 and 44- from the shaft 39 and with the circuit connections through the switches arranged such that current to motor 30 is controlled by switches 27 and 47, the frame 8 and hence motor 21 and impeller 22 will be shifted step-bystep in one direction about the axis of rotation. Furthermore, by removing the arms 43 and 44 and actuating the switch button 53a manually the blower unit will rotate continuously about its axis of rotation.

It is further self-evident that the step by step indexing in .one direction and the continuous movement in the opposite direction to the initial starting point can be accomplished mechanically instead of electrically by spring loading shaft 39 for the swing back with a ratchet and pawl arrangement actuated by a track cam for the step by step or indexing movement.

I claim: a 7 t 1. Apparatus for blowing off lint and other foreign particles which tend to collect upon exposed surfaces in a room containing textile machinery, comprising a generally horizontal trackway disposed in the room above the level of the machinery, a blower unit movable along said trackway, said blower unit including a motor and impeller driven thereby for producing a directional flow of air generally transverse to said trackway, means for indexing said blower unit for rotation about an axis parallel to said trackway in a step-by-step manner wherein the angle of the direction of the air fiow produced by said impeller is correspondingly indexed from a first position to a second position disposed less than 360 from said first position, and means actuatedwhen said blower unit has in said step-by-step manner reached 'said second position for returning the same quickly to said first position in a stepless manner to start a new cycle of step-by-step movement from said first to said second position.

2. Apparatus as defined in claim 1 wherein said blower unit is returned from said second position to said first position by angular movement in a direction which is the reverse of the step-by-step angular movement from said first position to said second position.

3. Apparatus for blowing off lint andother foreign particles which tend to collect upon exposed surfaces in a room containing textile machinery comprising a generally horizontal trackway disposed in the room above the level of the machinery, a blower unit movable a ong said trackway, said blower unit including a motor and impeller driven thereby mounted for rotation about an axis generally parallel to said trackway to deliver a directional flow of air generally transverse to said trackway, means for indexing said motor and impeller for step-by-step rotary movement thereof about said axis from a first position to a second position disposed less than 360 away from said first position, and means actuated when said motor and impeller have been indexed to said second position for returning the same quickly to said first position by continuous non-indexing movement.

4. Apparatus for blowing off lint and other foreign particles which tend to collect upon exposed surfaces in a room containing textile machinery, comprising a generally horizontal trackway disposed in the room above the level of the machinery, a blower unitmovable along said trackway, said blower unit including a motor and an. impe ler driven thereby, said motor being mounted for rotation about an axis generally parallel to said trackway' to deliver a directional flow of air generally transverse to said trackway,'and means for cyclically causing said motor and the impeller driven by it to be rotated about said axis forward and backwardtbetween twoplimiting positions over a predetermined angular path of less than 360", said means including means effecting step-by-step rotary displacements of said motor and impeller when rotating in said forward directionfrom an initial position, and means effecting continuous movement of said motor and impeller when rotating in said backward direction to regain said initial position. t

5. Apparatus for blowing off lint and other foreign particles which tend to collect upon exposed surfaces in a room containing textile machinery, comprising a generally horizontal trackway disposedin the room above the level of the machinery, a blower unit movable along said tracltway, said blower unit including a motor and an impeller driven thereby, said motor being mounted for tro-, tation about a horizontal axis extending generally parallel with'the direction of movement along said trackway in a plane generally transverse to said horizontal axis to deliver a' directional flow of air generally transverse tosaid trackway, and 'means for cyclically causing 'saidj motor and the impeller driven by itto 'berotated about ill said horizontal axis forward and backward between two limiting positions over a predetermined angular path of less than 360, said means including means indexing said motor and impeller for a step-by-step movement when rotating in said forward direction from an initial position, and means effecting continuous movement of said motor and impeller when rotating in said backward direction to regain said initial position.

6. Apparatus for blowing otf lint and other foreign particles which tend to collect upon the exposed surfaces in a room containing textile machinery, comprising a generally horizontal trackway disposed in the room above the level of the machinery, a blower unit movable along said trackway, said blower unit including a main frame mounted for rotation about a horizontal axis extending generally parallel with the direction of movement along said trackway, a secondary frame mounted for rotation within said main frame on an axis extending transverse to the axis of rotation of said main frame, a motor and impeller driven thereby mounted on said secondary frame, means for cyclica ly causing said main frame and hence also said secondary frame and motor and impeller to be rotated about said horizontal axis forward and backward between two limiting positions over a prede termined angular path of less than 360 to deliver a directional flow of air generally transverse to said trackway, said means including means indexing said main frame and hence also said secondary frame, motor and impeller for a step-by-step movement when rotating in said forward direction from an initial position and means effecting continuous movement of said main frame and hence also said secondary frame and motor and impeller when rotating in said backward direction to regain said initial position, and meansrotationally adjusting said secondary frame and hence also said motor and impeller about the axis of rotation of'said secondary, frame to different positions in said main frame for successive cycles of operation of said main frame.

. 7. Apparatus as defined in claim 6 and wherein said means for rotationally adjustingsaid secondary frame about its axis of rotation includes a multi-faced rotatable cam and cam follower transmitting movement to said secondary frame, and means rotating said cam for each cycle of operation of said main frame to present a differcut face to said cam follower, said cam faces being located at difi'erent distances from the cam axis of rotation thereby efiecting correspondingly different displacements of said cam follower and hence also different rotational dis-- placements of said secondary frame. 7

8. Apparatus for blowing off lint and other foreign particles which tend to collect upon exposed surfaces in a room containing textile machinery, comprising a generally horizontal trackway disposed in the room above the level of the machinery, a blower unit movable along said trackway, said blower unit including a first motor and impeller driven thereby supported by horizontal rotatable shaft means extending parallel with the direction of movement of said blower unit for rotation of said motor and impeller in a plane generally transverse to the direction of movement of said blower unit and trackway to deliver a directional flow of air generally transverse to said trackway, a second and reversible motor driving said shaft means, means periodically energizing said second motor to run in one direction for predetermined lengths of time thereby to cause said shaft meansand hence also said first motor and impeller to be indexed from an initial position to different 'angularly spaced blowing directions throughout a predetermined angular path of less than 360, and means actuated when said first motor and impeller reach the end of said angular path for reversing said second motor and causing the same to run continuously in the opposite direction until said shaftmeans and hence also said motor and impeller return to said initial position.

9. Apparatus for blowing olf lint and other foreign:

particles which tend to collect upon exposed surfaces in a room containing textile machinery, comprising a generally horizontal trackway disposed in the room above the level of the machinery, a blower unit movable along said trackway, said blower unit including a first motor and impeller driven thereby supported by a horizontal rotatable shaft means extending parallel with the direction of movement of said blower unit for rotation of said motor and impeller in a plane generally transverse to the direction of movement of said blower unit and trackway to deliver a directional flow of air generally transverse to said trackway, a second and reversible motor driving said shaft means, a cam rotatable with said shaft means, circuit means including first switch means actuated by said cam for energizing said second motor to run in one direction for predetermined lengths of time thereby to cause said shaft means and hence also said first motor and impeller to be indexed from an initial position to different angularly spaced blowing directions throughout a predetermined angular path of less than 360 and second switch means connected in said circuit means and actuated when said first motor and impeller reach the end of said angular path for reversing said second motor and causing the same to run continuously in the opposite direction until said shaft means and hence also said motor and impeller return to said initial position.

References Cited in the file of this patent UNITED STATES PATENTS 2,729,845 Miller et al Jan. 10, 1956 2,823,409 Allred Feb. 18, 1958 FOREIGN PATENTS 762,650 Great Britain Nov. 28, 1956 

